What is the correct term for the type of menu that is used for Slack's emoji reaction picker on mobile devices? The menu comes up from the bottom, can be pulled further up to the top of the page, and will "rubber band" back down to close itself once it's been dragged down past a certain threshold with your finger. Are there other examples in the wild that I can reference? Are there any web app-based (HTML/CSS/JS) implementations similar to this that I can take a look at?
It called bottom drawer/bottom sheet
Many apps used to present dropdown lists on separate pages a few years ago, but now the majority of apps use the bottom drawer with a drag gesture. We can use it to convey important information while maintaining the context of the current screen. It appears as an overlay, allowing the user to concentrate on a single, self-contained task. It is highly used in mobile apps.